Burglar-resistant lock



Oct. 16, 1962 c. WHITE 3,058,333

BURGLAR-RESISTANT LOCK Filed Aug. 8, 1960 2 Sheets-Sheet 1 mmvrqn. Clemens Whzie,

Oct. 16, 1962 c. WHITE 3,05

BURGLAR-RESISTANT LOCK Filed Aug. 8, 1960 2 Sheets-Sheet 2 l 5 12 30 7? 80 IE- I 66 64 2 8 4 IN VEN TOR.

Clemens W/zz'ic BY #z'iarneys ilnited rates Farmer ,1.

Filed Aug. s, 1964, Ser. No. 48,092 7 Claims. or. 76-15) This invention relates to locks, particularly door locks of the type adapted to be operated by a tumbler-type cylinder.

One object of the present invention is to provide a new and improved lock of the cylinder type which will offer great resistance to being opened, even after a burglar has pulled out the cylinder from the lock.

A further object is to provide a new and improved lock of the foregoing character, having means for positively preventing rotation of the bushing which normally receives the cylinder shaft, if the shaft is withdrawn from the bushing, as by the pulling of the cylinder.

Another object is to provide such a new and improved lock in which the withdrawal of the cylinder shaft releases a split tumbler or pin which thereupon locks the bushing against rotation, so that the lock cannot be opened with a screwdriver or other similar tool.

A further object is to provide a burglar-resistant con struction of the foregoing character which may be made at low cost for new locks, and which may readily be added to existing locks, as desired.

Further objects and advantages of the present invention will appear from the following description, taken with the accompanying drawings, in which:

FIG. 1 is a fragmentary, elevational view showing the outer side of a door equipped with a burglar-resistant lock, to be described as an illustraitve embodiment of the present invention.

FIG. 2 is a partly diagrammatic horizontal section taken generally along a line 2-2 in FIG. 1.

FIG. 3 is an elevational view showing the side of the lock which normally is mounted against the inside of the door, the view being taken as indicated by the line 33 in FIG. 2.

FIG. 4 is a cross sectional view, taken along the line 4-4 in FIG. 1.

FIG. 5 is an elevational view showing the inner side of the closure plate for the lock, the view being taken generally as indicated by the line 5-5 in FIG. 4.

FIG. 6 is a fragmentary enlarged sectional view, taken generally along a line 6-6 in FIG. 4.

The present invention is applicable to locks in general, but is shown in the drawing as applied to a door lock 10, of the type having a housing 12, adapted to be mounted on the inner side of a door 14. The lock 10 is adapted to be operated from the outside by means of a key 16, which may be inserted into a lock cylinder 18 of the tumbler type. It will be seen that the lock 10 has a knob 20 thereon for operating the lock from the inside.

A hole 22 is formed in the door 14 to receive the cylinder 18. It will be seen that the cylinder 18 is provided with a flange member 24 adapted to engage the outer face of the door around the hole 22. Behind the flange member 24, the cylinder has a portion 26 which fits closely in the hole 22. A reduced portion 28 extends rearwardly from the portion 26. A plurality of lock tumblers 29 may be mounted within the reduced portion 28.

Various arrangements may be employed for securing the lock cylinder 18 to the door 14. In this case, a plate 30, made of metal or the like, is mounted against the inner face of the door 14 so as to extend across the inner end of the hole 22. Two screws 32 extend through holes 34 in the plate and are screwed into tapped openings 36,

3,658,333 Patented Oct. 16, I962 rge formed in lugs 38 which project laterally from the reduced portion 28 of the cylinder 18.

The lock 10 is adapted to be operated by a non-circular shaft 42 extending rearwardly from the cylinder 18 into the housing 12. The shaft 42 is usually made in the form of a fiat bar adapted to be rotated by the key 16. Any suitable mechanism may be employed within the housing 12 so that the rotation of the shaft 42 will open the lock 10. In the illustrated arrangement, the flat shaft 42 extends through a rectangular slot or opening 44, which is formed in a rotatable bushing or hub 46. As shown to advantage in FIG. 2, the bushing 46 is rotatably supported by a member 47 which is mounted on a plate 48 adapted to close the side of the housing 12 facing toward the inside of the door 14. A radially projecting arm or finger 50 is secured to the inner end of the hub 46 for operating the lock mechanism. The plate 48 may be secured to the housing 12 by one or more screws 51 or the like.

It should not be thought that the present invention is limited to any particular type of lock cylinder or look mechanism. Thus, it is merely by way of example that the drawings illustrate the type of lock having a pair of jimmy-resistant bolts 53, which are movable vertically across slots 56 formed in the outer edge of the housing 12. As indicated in FIG. 1, the bolts 54 are adapted to interlock with apertured lugs 58 formed on a member 60 which is adapted to be mounted on the inside of the door jamb. The lugs 58 are adapted to be received in the slots 56 formed in the casing 12. The bolts 54 may be locked or unlocked by rotating either the knob 20 or the bushing 46.

At first glance, it might appear that the lock cylinder can be removed only by removing the screws 32 from the inside of the door. However, experience has demonstrated that a burglar can readily take hold of the cylinder flange 24 with a large pair of pliers, a toggle wrench, or the like, and can then exert sufficient force on the cylinder to pull it out of the door. In order to make the cylinder flange 24 difficult to grasp, it is formed with a tapering or beveled rim 61. Even so, a burglar can pull the cylinder quite readily. The force exerted by the burglar may pull the heads of the screws 32 through the holes 34 in the plate 30, or may break 011 the screws or the lugs 38.

The ordinary type of lock can readily be opened by the burglar, once the cylinder has been pulled. This can be .done, in the case of most prior locks, simply by inserting a screwdriver or the like through the hole 22 and into the rectangular slot 44 in the bushing 46. The bushing may then be rotated so as to open the lock.

However, the present lock is arranged so that the bushing 46 is locked against rotation as soon as the cylinder shaft 42 is pulled out of the slot 44 in the bushing. This is accomplished, in the illustrated embodiment, by providing the bushing 46 with a pin or tumbler 64 which is split into two parts 66 and 68. A diametrical opening or bore 7t) is formed in the bushing 46 to receive the tumbler 64. It will be seen that the tumbler 64 is also slidable into a radial bore or opening 72 formed in the stationary block or member 47 in which the bushing 46 is rotatable.

When the flat cylinder shaft 42 is in its normal position within the slot 44 in the bushing 46, the shaft 42 prevents the tumbler 64 from crossing the slot 44. The outer end of the tumbler pin 68 is biased against the shaft 42 by a spring 76 which engages the inner end of the tumbler pin 66 and is received in the bore 72. In this condition of the lock, the split between the tumbler pins 66 and 68 is aligned with the outer surface of the bushing 46, so that the bushing is free to rotate. When the bushing is rotated, the tumbler pin 66 remains in the stationary bore 72, while the tumbler pin 68 is carried along by the bushing.

When the cylinder shaft 42 is pulled out of the slot 44 in the bushing 46, the force of the spring 76 causes the tumbler pin 68 to move across the slot 44 into the opposite portion of the bore 70. A shoulder 77 in the bore 70 limits the movement of the pin 68 so that the split between the pins 66 and 68 will not be opposite the slot '44. At the same time, the tumbler pin 66 enters the bore 70 in the bushing 46. Thus, the tumbler pin 68 blocks the slot 44, while the pin 66 extends between the bores 70 and 72 and thus prevents rotation of the bushing 46. The tumbler pin 68 makes it diflicult to insert an ordinary screwdriver into the slot 44, but even if the burglar is able to insert a small screwdriver or a special tool into the unoccupied portions of the slot 44, the turnbler pin 66 effectively prevents rotation of the bushing 46 so that the lock cannot be opened. The presence of the tumbler pin 68 makes it very difficult and virtually impossible to drill out the pushing 46. Thus, the arrangement of the present invention provides effective protection against burglars. In most cases, a burglar will be likely to give up his attempt to open the door, rather than taking the time and making the noise necessary to demolish the lock.

The block or member 47 may be formed integrally with the closure plate 48 or may be welded or otherwise securely fastened thereto. In the illustrated arrangement, the member 47 is formed with studs 80 which are riveted to the plate 48.

To provide for normal assembly of the lock 10, when it is mounted on the door 14, a bore or opening 82 is provided through which a wire or other instrument may be inserted to push the tumbler pin 68 out of the slot 44 so that the cylinder shaft 42 may be inserted into the slot. In this case, the bore 82 is formed in a downwardly extending portion 84 of the block 47. At its lower end, the bore 82 is aligned with a hole 86 in the lock housing 12 so that a wire may readily be inserted into the bore 82. The upper end of the bore 82 is aligned with the bore 70 in the bushing 46, when the bushing is in its normal position. The bore 82 is disposed at a point diametrically opposite from the bore 72. Of course, the bore 82 opens on the inside of the door and thus is inaccessible to the burglar, but it is readily accessible to the mechanic when he installs the lock on the door.

It will be apparent that the present invention provides effective protection against burglars, yet is remarkably easy to manufacture and low in cost. It is possible to adapt the invention for use on existing locks, simply by providing a kit comprising the closure plate 48, the bushing 46, the block 47, and various components mounted on or assembled with the above-listed components. The existing lock is converted by substituting the plate 48 for the corresponding plate on the existing lock. It is then merely necessary to drill the hole 86 in the lock housing 12 so that a wire may be inserted into the bore 82. The ease with which existing locks may be converted has the effect of greatly widening the market for the present invention.

Various modifications, alternative constructions and equivalents may be employed Without departing from the true spirit and scope of the invention, as exemplified in the foregoing descriptions and defined in the following claims.

I claim:

1. In a lock, the combination comprising a lock cylinder having a flat shaft extending rearwardly therefrom, a housing having a bush-ing rotatable therein, a lock mechanism in said housing and operable by rotation of said bushing, said bushing having a slot therein disengageably receiving said fiat shaft, a stationary member adjacent said bushing, a first radial bore in said member and a second bore in said bushing and movable into alignment with said first bore, a split tumbler having first and second tumbler pins slidable in said bores, a spring biasing said tumbler pins in a radially inward direction, said second bore opening into said slot, said second tumbler pin normally being held out of said slot by said fiat shaft, the split between said pins normally being aligned with the outside of said bushing so that said bushing is free to rotate when said shaft is received in said slot, said spring being effective to move said second tumbler pin across said slot and to move said first tumbler pin into said second bore to lock said bushing against rotation when said shaft is withdrawn from said slot.

2. In a lock, the combination comprising a lock cylinder having a non-circular shaft extending rearwardly therefrom, a lock mechanism having a stationary member thereon, a bushing rotatable in said stationary member for operating said lock mechanism, said bushing having a non-circular slot therein disengageably receiving said shaft, a first radial bore in said stationary member, a second bore in said bushing and normally aligned with said first bore, first and second tumbler pins slidable in said bores, and a spring biasing said tumbler pins inwardly along said bores, said second tumbler pin normally being held out of said slot by said shaft and normally having its outer end aligned with the outside of said bushing so that said bushing will be free to rotate, said spring being effective to move said second tumbler pin into said slot while moving said first tumbler pin into said second bore to lock said bushing against rotation when said shaft is withdrawn from said slot.

3. In a lock, the combination comprising a lock cylinder having a non-circular shaft extending rearwardly therefrom, a lock mechanism having a second shaft rotatable therein for operating said lock mechanism, said second shaft having a non-circular opening therein for disengageably receiving said first shaft, a stationary member adjacent said second shaft, a first bore in said stationary member, a second bore in said second shaft and movable into alignment with said first bore, first and second tumbler pins movable in said bores, and a spring biasing said tumbler pins inwardly along said bores, said tumbler pins being effective to lock said second shaft against rotation when said first shaft is withdrawn from said opening, and a third bore in said member and opposite from said first bore forreceiving a tool to reset said tumbler pins.

4. In a lock, the combination comprising a lock cylinder having a non-circular shaft extending rearwardly therefrom, a lock mechanism having a stationary member thereon, a bushing rotatable in said stationary member for operating said lock mechanism, said bushing having a non-circular slot therein disengageab-ly receiving said shaft, a first radial bore in said member, a second bore in said bushing and normally aligned with said first bore, first and second tumbler pins slidable in said bores, a spring biasing said tumbler pins inwardly along said bores, said second tumbler pin normally being held out of said slot by said shaft and normally having its outer end aligned with the outside of said bushing so that said bushing will be free to rotate, said spring being effective to move said second tumbler pin into said slot while moving said first tumbler pin into said second bore to lock said bushing against rotation when said shaft is withdrawn from said slot, and a third bore in said member for receiving a tool to reset said tumbler pins.

5. In a lock, the combination comprising a lock cylinder having a flat shaft extending rearwardly therefrom, a housing having a bushing rotatable therein, a lock mechanism in said housing and operable by rotation of said bushing, said bushing having a slot therein disengageably receiving said fiat shaft, a stationary member adjacent said bushing, a first radial bore in said member and a second bore in said bushing and movable into alignment with said first bore, a split tumbler having first and second tumbler pins slidable in said bores, a spring biasing said tumbler pins in a radially inward direction, said second bore opening into said slot, said second tumbler pin normally being held out of said slot by said flat shaft, the split between said pins normally being aligned with the outside of said bushing so that said bushing is free to rotate when said shaft is received in said slot, said spring being efiective to move said second tumbler pin across said slot and to move said first tumbler pin into said second bore to lock said bushing against rotation when said shaft is withdrawn from said slot, and a third bore in said stationary member and opposite from said first bore for receiving a tool to reset said tumbler pins.

6. In a lock, the combination comprising a lock cylinder having a non-circular shaft extending rearwardly therefrom, a lock mechanism having a stationary member thereon, a bushing rotatable in said stationary member for operating said lock mechanism, said bushing having a non-circular slot therein disengageably receiving said shaft, a first opening in said stationary member, a second opening in said bushing and normally aligned with said first opening, tumbler means slidable in said openings, and spring means biasing said tumbler means into said slot, said tumbler means normally being held out of said slot by said shaft and normally being aligned with the outside of said bushing so that said bushing will be free to rotate, said spring being effective to move said tumbler means into said slot and out of alignment with the outside of said bushing to lock said bushing against rotation when said shaft is withdrawn from said slot.

7. In a lock, the combination comprising a lock cylinder having a cylinder shaft extending rearwardly therefrom, a lock mechanism having an operating shaft rotatably mounted thereon for operating said lock mechanism, said lock mechanism having a stationary member adjacent said operating shaft, said operating shaft having means disengageably interlocking with said cylinder shaft, a first tumbler opening in said stationary member, a second tumbler opening in said operating shaft and normally aligned with said first tumbler opening, tumbler means movable in said openings between an unlocking position and a locking position, said tumbler means when in said unlocking position being aligned with the outside of said operating shaft to provide for free rotation of said operating shaft, said tumbler means when in said locking position extending in said tumbler openings between said stationary member and said operating shaft to block said operating shaft against rotation, and spring means biasing said tumbler means for movement between said unlocking and locking positions, said cylinder shaft having a portion normally blocking said tumbler means in said unlocking position, said spring means being effective to move said tumbler means to said locking position to lock said operating shaft against rotation when said cylinder shaft is disengaged from said operating shaft.

References Cited in the file of this patent 4 UNITED STATES PATENTS 591,200 Stevenson Oct. 5, 1897 1,387,245 Dowling Aug. 9', 1921 1,764,898 Segal June 17, 1930 2,942,449 White June 28, 1960 

